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Free Online Calculators

1014+ engineering, math, physics, chemistry, biology, finance, health, statistics, and everyday calculators — all free, no signup required.

MegaCalc offers a comprehensive library of free online calculators covering engineering, science, mathematics, finance, and everyday use. Every calculator runs entirely in your browser — results appear instantly as you type, with no page reloads, no server round-trips, and no data stored or transmitted. All calculators support both metric (SI) and imperial unit systems, with unit selectors on every input field so you can work in the units your problem calls for.

The engineering calculators span the full undergraduate mechanical engineering curriculum: statics, dynamics, mechanics of materials, thermodynamics, fluid mechanics, heat transfer, machine design, materials science, and manufacturing. Each calculator implements the governing equation with clearly labeled variables, a step-by-step guide, and a formula reference — making these tools useful for both learning and professional practice.

What Calculators Are Available?

Statics

Force resolution, moments, centroids, trusses, and area moments of inertia.

Dynamics

Projectile motion, circular motion, work-energy, impulse-momentum, and gear ratios.

Mechanics of Materials

Stress, strain, Hooke's law, beam bending, torsion, buckling, and fatigue.

Thermodynamics

Ideal gas law, Carnot efficiency, Otto and Diesel cycles, Rankine cycle, and psychrometrics.

Fluid Mechanics

Reynolds number, Bernoulli, Darcy-Weisbach, pump power, orifice flow, and drag.

Heat Transfer

Conduction, convection, radiation, heat exchangers (LMTD and NTU), and fin efficiency.

Machine Design

Shaft design, bearing life, belt drives, spring design, bolt preload, and weld strength.

Materials Science

Hardness conversion, thermal expansion, stress-strain properties, and creep life.

Manufacturing

Machining parameters, turning operations, drilling, tolerance stack-up, and surface finish.

Finance

Mortgage, compound interest, sales tax, discount, and percentage calculators.

Health

BMI calculator and other health and fitness metrics.

Everyday

Age, tip, days between dates, pace, download time, and aspect ratio calculators.

Controls & Systems

Transfer functions, Bode plots, root locus, PID tuning, Routh-Hurwitz, Nyquist, state-space, and Z-transform.

Engineering Statistics

Normal and t-distributions, ANOVA, regression, chi-square, DOE, process capability, and Weibull analysis.

Mechanical Vibrations

Free and forced SDOF vibration, vibration isolation, critical speed, dynamic absorbers, FFT, and multi-DOF systems.

Electrical Circuits

Ohm's law, AC impedance, RLC circuits, transformers, motors, voltage dividers, and Wheatstone bridges.

Engineering Economics

Time value of money, NPV, IRR, depreciation, break-even, loan amortization, and rate of return.

Numerical Methods

Root finding, numerical integration, ODE solvers, curve fitting, matrix operations, and interpolation.

Measurement & Instrumentation

Uncertainty propagation, sensor calibration, SNR, strain gauges, thermocouples, and ADC resolution.